Spatial diversity in wireless communications involves the communication of the same data using multiple data paths. The quality of the wireless link, or channel, associated with each data path may differ because each channel may experience a different interference environment. Multiple transmissions of the same data may be combined at the receiver to improve signal reception.
Certain types of wireless environments, such as Wi-Fi and cellular mobile device communications, typically involve one or more relatively fixed-location controller nodes, such as Wi-Fi access points, or cellular base stations, respectively, and multiple mobile devices that are serviced concurrently by the controller node. Some mobile devices, at least for a period of time, may be within wireless range of other mobile devices that are being serviced by the same controller node, and thus, if such mobile devices were suitably coordinated during such period of time, may be able to receive messages from another mobile device and re-transmit the messages to the controller node, thereby implementing spatial diversity for the message transmission and increasing a likelihood of successful wireless data communication with the controller node.
However, multiple factors may affect whether or not any particular mobile device's participation in such coordinated efforts would be desirable, including, for example, the quality of the channel between the coordinating mobile device and the message-originating mobile device, the quality of the channel between the coordinating mobile device and the controller node, the availability or idle state of the coordinating mobile device at or substantially near the transmission time of the message-originating mobile device, whether or not re-transmissions by the coordinating mobile device increase interference with a neighboring controller node, and the like. A controller node may be unaware of one or more these factors. Moreover, even if these factors were known to a controller node, the mobile devices that would be useful in implementing spatial diversity would require knowledge of their role. Accordingly, there is a need for mechanisms by which a controller node can acquire information suitable for identifying a cluster set of mobile devices for implementing spatial diversity, as well as mechanisms for coordinating actions by such mobile devices.